Electrical terminal detecting signal



July 21, 1953 w. v. EAKINS ELECTRICAL TERMINAL DETECTING SIGNAL 2Sheets-Sheet 1 Filed March 15, 1951 I lnnentor M7//Z7/77 K [22/0/25attorneys July 21, 1953 w. v. EAKINS ELECTRICAL TERMINAL DETECTINGSIGNAL 2 Sheets-Sheet 2 Filed March 15, 1951 m E E 2 r o a m INVENTOR.VV/L/AM-MfAK/NS ATTORNEYS.

Patented July 21, 1953 STATES PA ENT OFFICE SIGNAL William V. Eakins,Buffalo, N. Y, Y ApplicationiMarch 15, 1951, Serial No. 215,750

8 Claims. (01. 116114) This invention relates to electrical connectorsandparticularly to signaling, warning, or telltale means for quicklylocating loose electrical connections I I i a v Incor ventionalelectrical terminal where the ends Yof conductors are heldv in terminalsockets by set-screws or similar devices or where the conductor ends areotherwise clamped to a terminal device the connection may be looseenough to make a poor contact or no contact at all while the end of theconductor might still appear to be in the socket or other clamp andproperly connected, so that the defect would not be apparent on casualinspection. thus be spent in locating trouble of this natureparticularly in the case of extensive electrical panel boards, inindustrial and like applications.

The device of the present invention provides means whereby a looseterminal may be located by merely scanning an electrical panel board oran aggregation of electrical apparatus or 'devices. Speaking generally,this is accomplished, in accordance'with the principlesof the presentinvention, by providing an electrical connector so arranged that amoderate'tension force'is exertedon'the conductor tending'to pull itfrom the terminal socket. In combination with the ten"-sioningmeansthere is'provided a visual signal or telltale which is"operable by an'dupon'the disconnecting movement of a loose conductorwhich signal mayreadily be located.

By way of example'there are disclosed herein two'embodiments of theprinciples of th'e'pr'esent invention, onewherein a, conductor is heldin connection with a. terminalas at a panel or the like, and one whereintwo conductors are connectedv to each other in'end-to-end relation toform an electrically continuous conductor. It is to "be understood thatthese embodiments are by way of example only, and that many mechanicalmodifications may be made without departing from the spirit of thepresent invention, the scope of which is limited only as defined in theappended claims.

' In the drawing: I

Fig. 1 is 9, perspectiveview, partly'broken' away foraddedillustration,of one'form of the connecting and signalling means of the preesnt invention'; V

Fig; 2 is'a longitudinal cross-sectional view of another form of theconnecting and signaling means of the present invention;

Fig. 3 is a cross-sectional view taken approximately on the line.IIIIIIof Fig. 2; and

Fig. 4 is a cross sectional'vie'W taken approxi- Much time may Likecharacters of reference denote like parts i and, referring to Fig. 1,the numeral I0 designates a conducting bar which may be a bus bar orapart of anf electrical .Iterminal panel or the like. The numeral IIdesignates a metallic strap having a base portion I2 and an end flangei3, an opposite end flange I4, and a return. bent portion I5. The returnbent portion is of channel formation and is adapted toreceive a. clip .I6 of generally channel formation. A screw I] threads into bar I0 toretain the strap I I and the clip I 6 in their illustrated assembledposition.

Cli I6 further cooperates'with strap I2 to engage and clamp th end of anelectrical conductor in a manner which will presently'be described. Ablock, 20' which may conveniently comprise insulating materialsuch assynthetic resin orv the like is rigidly assembled with strap I2 betweenflange 1'3 and the end of return bent portion I5 and in production maybe molded directlyin placeon strap I2. Block 20 is provided with arectangular-Opening 2| in its upper face in which is assembled forvertical sliding movement a further blockof insulating materialdesignated 22. A compression coil spring 23 seats in the bottom of'theopening 2! and normally bears against the bottom of insulating block 22.

Block 22 is provided with a longitudinal axial bore for receiving aninsulated conductor 25 and the opposite ends of block 20 are providedwith openings 21, preferablyin the form of vertically elongated slots.'Block22 is a plain rectangular block resting on the top of spring 23and its longitudinal axial bore is only slightly larger in diameter thanthe insulated conductor '25 as shows best in Fig.4.

Conductor 25 is threaded through the slots 21 and the bore in'b1ock.22with block'22 held manuallydepressed to the approximat position in whichitlis i llustrated in Fig. 1, and the bare end of conductor"25 is thenclamped between strap l2 and clip I6 as'is clearly illustrated .at 29 inFig. 1 When screw I1 is tight andthe end'of conductor 25 is firmlygripped the block 2215 prevented from moving upwardly from thepositionillustrated in'Fig. 1, the upwardurge of spring 23 being relatively,light and not great enough to materially deform the insulated bodyportion of conductor 25.

However, if th screw I! should become loose or if the bare end oftheconductor should break near its clamped end 29, the spring 23 willurge block 22' upwardly until the conductor engages the upperendsofjtheslots 21, which slots are proportioned I to properly 11mmupward movement of theblock -22 ahditgassembled"conductor.

This will expose a substantial portion of the upper part of block 22above the top of block 20. The upper or signaling position of block 22is indicated in dot-and-dash lines at the top of Fig. 4. Block 22 may beentirely of material of a color contrasting with the color of block 20,or its side walls may be thus contra-stingly colored. In either eventthe exposure of a portion of block 22 above block will thus afford aneasily located signal indicating the failure of the electricalconnection at that terminal.

Since the screw [1 which provides the wire clamping force also holds theentire clamping device to the bus bar or terminal strip l0, a warningsignal will also indicate that the'clamping device is not securely fixedto .the bus bar or terminal strip.

Referring to the embodiment illustrated in longitudinal cross-section inFig. 2, the numerals and 3i designate a pair of insulated conductorswhich are connected in end-to-end conducting relation. The numeral 32designates an outer protective sleeve of fiber, synthetic resin, orother insulating material. The numeral 33 designates an intermediatetelescoping sleeve, likewise of insulating material having an end wall34. Sleeves 32 and 33 are separable axially but relatively fixed inoperation by virtue of a threaded connection which is indicated at 31 inFig. 2. The numeral 35 designates an inner telescoping sleeve, likewiseof insulating material, having an end wall 38. The sleeves 33 and 35 aremounted for axial intersliding movement.

Sleeve 33 has fixed thereto an internal transverse bar formation 38which may be molded integrally therewith, and inner sleeve 35 islikewise provided with a transverse rigid bar formation 39. Acompression coil spring normally urges the bars 38 and 39 away from eachother and a supporting and protecting sleeve 4| for spring 40 may beprovided. In the present instance sleeve 4| is secured at one end to bar39 in any desired manner.

The portions of the bars 38 and 39 which face outwardly of the tubularassembly are rounded as shown in Fig. 2, and the conductors 30 and 3iwrap around the bars 33 and 39, respectively, andthe bare ends of theconductors 30 and 31 .are held between the opposite ends of a pair ofclamp plates 44 and 45 by a clamping screw 46 which passes freelythrough plate 45 and threads into plate 44. The sleeves 33 and 35 areapertured as indicated at 41 to permit access to screw 46 for tighteningor loosening the same, outer sleeve 32 being unscrewed and slid endwiseout of the way during such operations.

Sleeve 35 is of a contrasting color from that of sleeve 32, or at leastits outer peripheral wall is so colored. Accordingly, if either or bothof the conductors were to pull out of the clamp assembly due to thescrew 46 being loose, or if the wires of the conductors should break offclose to the clamp members 44 and 45, the spring 45 would urge thesleeve 35 axially outwardly of the sleeves 32 and 33 and thus expose thecolored peripheral portions of sleeve 35 to afford a ready indication ofthe failure.

What is claimed is:

1. Electrical terminal means comprising a releasable clamp, meansadjacent to said clamp engaging against a conductor having its endengaged in said clamp and bearing against said conductor in a directiongenerally outwardly of said clamp, resilient means urging saidengagingmeans to withdraw the conductor end from said 4 clamp when the clamp isloose, and signal means on said engaging means rendered visible by suchmovement of the engaging means.

2. Electrical terminal means comprising a re leasable clamp adapted toclamp the end portion of an electrical conductor, abutment meansadjacent to said clamp with the conductor bent to lie thereagainst, saidabutment being movable to withdraw the conductor from the clamp when thelatter is loose, resilient means urging said abutment means to sowithdraw a conductor, and signal means movable with said abutment meansand rendered visible by movement thereof to separate a conductor fromits clamp means.

3. Electrical terminal means comprising a releasable clamp, meansadjacent to said clamp en- ,gaging against a conductor having its endengaged in said clamp and bearing against said conductor to tend towithdraw the conductor from said clamp, and signal means on saidengaging means rendered visisble by such withdrawing movement of theengaging means.

4. Electrical terminal means comprising a releasable clamp,meansadjacent to said clamp engaging against a conductor having its endengaged in said clamp and bearing against said conductor, resilientmeans urging said engaging means to tend to Withdraw the conductor endfrom said clamp, and signal means on said engaging means renderedvisible by conductorwithdrawing movement of the engaging means.

5. Electrical terminal means comprising a releasable clamp adapted toclamp a pair of electrical conductors in end-to-end relation, a pair ofabutment members adjacent to said clamp, resilient means urging saidabutment means apart whereby with the clamped conductors wrapped aboutthe abutment means in return bent fashion the abutments tend to withdrawthe conductors from the clamp, and signal means movable with saidabutment means and rendered visible by movement thereof in withdrawing aconductor from its clamp means.

6. Electrical terminal means comprising a releasable clamp adapted toclamp the end portion of an electrical conductor with the adjacentportion of the conductor extending away from the clamp, abutment meansadjacent to said clamp and movable in a direction generally parallel tosaid adjacent conductor portion, resilient means urging said abutmentmeans in a direction gen erally away from the clamp whereby when theconductor is bent to lie across the abutment means the latter tends towithdraw the conductor from the clamp, and signal means movable withsaid abutment means and rendered visible by movement thereof to separatea conductor from its clamp means.

'7. Electrical connector means comprising a releasable clamp forconnecting the end portions of a pair of electrical conductors inend-to-end relation, a pair of abutments adjacent said clamp and mountedfor sliding movement in a direction parallel to the end portions of theconductors, each of said conductors being adapted to extend across oneof the abutments, spring means urging said abutments away from eachother to exert a disconnecting pull on each of said conductors, andsignal means rendered visible by movement of said abutments upondisconnecting movement.

8. Electrical connector means comprising a pair of slidable telescopingsleeves and a releasable clamp therein for connecting the end portionsof a pair of electrical conductors in end-to-end rela-- tion, a pair ofabutments adjacent said clamp and mounted one on each of said sleevesfor sliding movement therewith in a direction parallel to the endportions of the conductors, each of said conductors being adapted to beWrapped across one of the abutments, spring means urging said abutmentsaway from each other to exert a disconnecting pull on each of saidconductors, and signal means on one sleeve rendered visible by movementof said abutments upon disconnecting movement.

WILLIAM V. EAKINS.

References Cited in the file of this patent UNITED STATES PATENTS Number

